Abstract: A cyclone for treating pulverous raw material suspended in a hot gas stream, for use, for example, in a suspension preheater plant for treating cement raw materials and similar materials, comprises a tubular chamber with a vertical axis, a cone shaped bottom with a central outlet for precipitated material, a central outlet for hot gases at the top of the chamber and a tangential inlet for hot air. The inlet has a chamfered wall causing the suspension stream entering the cyclone through the duct leading to the inlet to be deflected outwards against the inner surface of the chamber wall and downwards into the cyclone chamber.